Use SharedPersistentMemoryAllocator to share field trial state

content/browser/browser_child_process_host_impl.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_BROWSER_BROWSER_CHILD_PROCESS_HOST_IMPL_H_
 #define CONTENT_BROWSER_BROWSER_CHILD_PROCESS_HOST_IMPL_H_
 
 #include <stdint.h>
 
 #include <list>
@@ skipping 48 matching lines @@
                               const std::string& service_name);
   ~BrowserChildProcessHostImpl() override;
 
   // Terminates all child processes and deletes each BrowserChildProcessHost
   // instance.
   static void TerminateAll();
 
   // Copies kEnableFeatures and kDisableFeatures to the command line. Generates
   // them from the FeatureList override state, to take into account overrides
   // from FieldTrials.
-  static std::unique_ptr<base::SharedMemory> CopyFeatureAndFieldTrialFlags(
-      base::CommandLine* cmd_line);
+  static void CopyFeatureAndFieldTrialFlags(base::CommandLine* cmd_line);
 
   // BrowserChildProcessHost implementation:
   bool Send(IPC::Message* message) override;
   void Launch(SandboxedProcessLauncherDelegate* delegate,
               base::CommandLine* cmd_line,
-              const base::SharedMemory* field_trial_state,
               bool terminate_on_shutdown) override;
   const ChildProcessData& GetData() const override;
   ChildProcessHost* GetHost() const override;
   base::TerminationStatus GetTerminationStatus(bool known_dead,
                                                int* exit_code) override;
   std::unique_ptr<base::SharedPersistentMemoryAllocator> TakeMetricsAllocator()
       override;
   void SetName(const base::string16& name) override;
   void SetHandle(base::ProcessHandle handle) override;
 
@@ skipping 87 matching lines @@
 
   bool is_channel_connected_;
   bool notify_child_disconnected_;
 
   base::WeakPtrFactory<BrowserChildProcessHostImpl> weak_factory_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_BROWSER_CHILD_PROCESS_HOST_IMPL_H_